1. Field of the Invention
This invention relates to temperature measurement systems and, more particularly, to resistance temperature device (RTD) measurement mechanisms.
2. Description of the Related Art
Resistance temperature devices or detectors (RTDs) are temperature-sensing devices whose resistance increases with temperature. RTDs typically consist of a wire coil or a deposited film of pure metal. RTDs are known for their excellent accuracy over a wide temperature range. Since RTDs are resistive devices, an RTD measurement device drives a current through the RTD and measures the resulting voltage to determine the temperature associated with an RTD.
Two of the most widely used RTDs have a 3-wire or a 4-wire configuration. If a device under test (DUT) includes an RTD with a 3-wire configuration, an RTD measurement unit configured to operate in a 3-wire RTD mode is usually required. Similarly, if a DUT includes an RTD with a 4-wire configuration, an RTD measurement unit configured to operate in a 4-wire RTD mode is typically required. Alternatively, some RTD measurement units are configurable via software to operate in either a 3-wire RTD mode or a 4-wire RTD mode. However, these configurable RTD measurement units require a user to manually configure the device to operate in one of the two RTD modes.